Chapter 24

Chapter 24: Valvular Disorders of the Heart

Heart Structures

  • Four Cardiac Valves:

    • Aortic valve

    • Mitral valve

    • Tricuspid valve

    • Pulmonic valve

  • Types of Affected Conditions:

    • Malformations at birth

    • Inflammatory and infectious disorders

    • Age-related degeneration

    • Structural damage after myocardial infarction (MI)

    • Injury from intracardiac procedures

  • Location of Valves:

    • Left side of heart: Aortic and Mitral valves

    • Right side of heart: Pulmonic and Tricuspid valves

Heart Valve Diagram

  • Description of valve mechanics during phases of heart function:

    • Relaxation Phase (Diastole):

    • Mitral and Tricuspid valves are open

    • Aortic and Pulmonic valves are closed

    • Contraction Phase (Systole):

    • Aortic and Pulmonic valves are open

    • Mitral and Tricuspid valves are closed

Aortic Stenosis

  • Definition:

    • Narrowing of the opening in the aortic valve; valve cusps become stiff and rigid.

  • Pathophysiology:

    • The muscular wall of the left ventricle enlarges and thickens in response to a stiff, calcified valve.

  • Causes:

    • Older adults: degenerative change

    • Young adults: congenital defect

    • Rheumatic carditis

    • Infective endocarditis

Diagnostic Tests

  • Chest X-ray

  • Echocardiogram

  • Electrocardiogram (ECG)

  • Cardiac catheterization

Assessment Findings

  • Symptoms of dyspnea and fatigue during activity

  • Dizziness and fainting

  • Angina (chest pain)

  • Weak carotid pulse

  • Split S2 heart sound (“lub-t-tub”)

Nursing Care

  • Monitor symptoms closely

  • Administer prescribed medications:

    • Diuretics

    • Antibiotics

    • Nitrates

    • Beta-adrenergic blockers

  • Institute measures for adequate cardiac output and tissue oxygenation

  • Recommendation of a low sodium diet

  • Surgical Management:

    • Balloon valvuloplasty

    • Aortic valve replacement

    • Transcatheter aortic valve implantation

Aortic Regurgitation

  • Definition:

    • Aortic valve does not close tightly, allowing blood to leak backward.

  • Consequences:

    • Progresses to left ventricle hypertrophy and left-sided heart failure (HF).

  • Causes:

    • Damage to valve cusps or papillary muscles

    • Rheumatic carditis, endocarditis

    • Age-related stretching of proximal aorta

    • Systemic inflammatory conditions

    • Medications (e.g., Fen-Phen, Redux)

Assessment Findings

  • Initial: Palpitations when lying flat or on the left side

  • Later stages:

    • Dyspnea

    • Chest pain

    • Tachycardia

    • Widening pulse pressure

    • Flushed or moist skin

  • Heart murmur may be detected

Nursing Care

  • Report changes in heart rate and rhythm

  • Monitor for symptoms of dyspnea, chest pain, and syncope

  • Prophylactic antibiotic therapy recommendations

  • Blood pressure teaching

  • Medications:

    • Cardiac glycosides

    • Beta-blockers

    • Diuretics

    • Prophylactic antibiotics

  • Recommendation of a low sodium diet

  • Surgical Management:

    • Aortic valve replacement

    • Vascular graft

Mitral Valve Stenosis

  • Definition:

    • Condition of the mitral valve (bicuspid valve) between the left atrium and left ventricle affecting stroke volume.

  • Causes:

    • Rheumatic carditis

    • Recurrence of endocarditis

    • Inflammation causes thickened and rigid commissures due to scarring

  • Consequences:

    • Incomplete emptying can lead to arterial emboli, pulmonary hypertension, and right-sided heart failure.

Diagnostic Tests

  • Chest X-ray

  • Esophageal echocardiogram

  • Electrocardiogram (ECG)

Assessment Findings

  • Fatigue and dyspnea after minimal exertion

  • Tachydysrhythmias

  • Experience dyspnea at night and may need to sleep in a sitting position

  • Cough productive of pink, frothy sputum; crackles may be heard

  • Changes in heart sounds detected

  • Neck vein distention

  • Peripheral edema

Nursing Care

  • Monitor patient's physical condition, diagnostic testing, and post-treatment care

  • Provide discharge teaching regarding drug therapy and signs of complications

  • Medications include antibiotics and therapies to prevent or relieve symptoms of HF, including:

    • Daily aspirin

    • Anticoagulants

  • Surgical Management:

    • Commissurotomy

    • Cardioversion

    • Percutaneous balloon valvuloplasty

Mitral Valve Regurgitation

  • Definition:

    • Condition where blood flows backward into the left atrium during ventricular systole and leaks into left ventricle during atrial diastole, leading to cardiogenic shock.

  • Causes:

    • Rheumatic carditis

    • Mitral valve prolapse

    • Damage to papillary muscles

    • Impaired myocardial function after myocardial infarction (MI)

Assessment Findings

  • Chronic fatigue

  • Dyspnea on exertion

  • Palpitations and tachycardia

  • Diminished S1 heart sound

  • Hypertension (HTN)

  • Heart murmur detected

Nursing Care

  • Monitor blood pressure, heart rate, and rhythm

  • Assess heart sounds and lung sounds

  • Report signs of left-sided or right-sided HF

  • Patient education regarding prophylactic antibiotics

  • Medications include:

    • Angiotensin-converting enzyme (Accupril)

    • Angiotensin receptor blocker (losartan)

    • Digitalis

    • Calcium channel blockers

    • Beta-blockers

    • Antidysrhythmic drugs

  • Surgical Management:

    • Intra-aortic balloon pump

    • Annuloplasty

    • Valve replacements

Mitral Valve Prolapse

  • Definition:

    • Condition where valve cusps enlarge, become floppy, and bulge backward into the left atrium.

  • Demographics:

    • More common in young women than men

  • Causes:

    • Idiopathic

    • Rheumatic carditis

    • Hereditary connective tissue disorders

    • Coronary artery disease (CAD)

  • Condition Associated:

    • Mitral valve prolapse syndrome: autonomic nervous system dysfunction

Diagnostic Tests

  • Echocardiography

  • Electrocardiogram (ECG)

Assessment Findings

  • Often asymptomatic

  • Chest pain (angina) not correlating with exertion, prolonged, and not easily relieved

  • Palpitations including rapid and irregular heart rate

  • Experiences fatigue and anxiety

  • Shortness of breath

  • Light-headedness and difficulty concentrating

  • Characteristic “click” sound may be heard during ventricular systole

Nursing Care

  • To relieve chest pain, recommended to lie flat with legs elevated at 90°

  • Recommendations to restrict alcohol and avoid caffeine

  • Promote adequate hydration, exercise, and monitor blood pressure

  • Medications may include:

    • Antibiotic therapy

    • Digitalis

    • Beta-blockers

    • Calcium channel blockers

    • Low-dose aspirin

    • Antianxiety medications

  • Surgical Management:

    • Valve replacement

  • Remembering the Heart Valves:

    • Reference: https://www.youtube.com/watch?v=i64nLFQTU5E